1. Field of the Invention
The present invention relates generally to spark plugs for igniting combustion gases in a combustion chamber of an internal combustion engine, and more particularly to extension-type spark plugs used in applications having limited access space.
2. Related Art
Spark plugs are used in a variety of internal combustion engine applications and are configured along with other accessory parts to fit within a given operating environment. For example, in a particular engine application the depth of a bore in the engine in which the spark plug is received may require the use of a separate spark plug extension to connect the spark plug to a spark plug wire. While designs with accessory extension pieces generally meet their intended purpose, problems still persist. For example, spark plug designs having multiple separate pieces can cause manufacturing and service logistic issues, aside from adding cost to the manufacturing process. Further, the more complex designs require retrofit instructions. Moreover, such designs having multiple separate pieces require field assembly and, thus, have a reduced reliability.
Therefore, it would be desirable to reduce the number of separate components required to install a spark plug in a given operating environment to reduce assembly complexity and costs associated therewith. Moreover, the new and improved spark plug design should be economical in manufacture and exhibit a long and useful life.